Telephone system



Aug. 1, 1933. E Q Z IE S 1,920,230

TELEPHONE SYSTEM Filed July 28, 1931 3 Sheets-Sheet l INVENTOR EDUARD O.ZWIETUSCH ATTORNEY g- 1, 1933- E. o. ZWIETUSCH 1,920,230

TELEPHONE SYSTEM Filed July 28, 1931 3 Sheets-Sheet 2 INVENTOR EDUARD O.ZWIETUSCH ATTORNEY 8- ,1933. E. o. ZWIETUSCH 1,920,230

TELEPHONE SYSTEM Filed July 28, 1931 3 Sheets-Sheet 3 m rr WWW M 16 lNVENTOR EDUARD O. ZWIETUSCH ATTORNEY Patented Aug. 1, 1933 UNITED STATESTELEPHONE SYSTEM Eduard O. Zwietusch, Beriin-Steglitz, Germany, assignorto International Communications Laboratories, Inc., New York, N. Y., aCorporation of New York Application July 28, 1931, Serial No. 553,592,and in Germany August 15, 193

16 Claims. (01. 175-339.)

My invention relates to improvements in the adjustment ofelectromagnetic devices used in loud speakers or in telephone ringers.The object of my invention is the design of such devices wherein thepole pieces and armature are accurately positioned in relation to oneanother to' obtain the greatest sensitivity.

My invention provides an adjusting arrangement which allows theindividual pole pieces or the similar pairs of pole pieces to be moveddif ferent distances from the armature.

The adjustment of the pole pieces or pairs of pole pieces to differentdistances in respect to the armature is performed by an adjusting memberwhose moving axis is displaced against the symmetrical axis of the polepieces.

The two similar pole pieces are each pivoted around a common axis andmovement of the pole pieces is in arc pathswhen approaching or movingaway from the armature.

Various features of my invention will be pointed out in the descriptionto follow.-

My invention is illustrated in the accompanying drawings which show theessential features:

Fig. 1 is a side view, partly in section, showing the adjusting featuresapplied to a loud speaker unit.

Fig. 2 is an end view of the pole pieces shown in Fig. 1. I

Fig. 3 is a schematic drawing showing the varying positions assumed bythe armature and pole pieces. V i r Fig. 4 is a plan view showing theadjusting features as applied to a telephone ringer.

Fig.5 is a side view of Fig. 4.

Fig. 6 is a plan view of a still further modification.

Fig. 'Z'is a side view of Fig. 6, partly in section.

Fig. 8 is a schematic drawing showing the po-.

sitions assumed by the armature and pole pieces.

In the embodiments of the invention which have been chosen for purposesof illustration in Figs. 1 and 2 are shown a permanent magnet 1 of thehorseshoe type mounted upon a frame or support 23. Two pole pieces,respectively ineluding pole ends 2, 3 and 4, 5 formed on suitable bodyportions, are pivotally mounted on opposite branches of the permanentmagnet 1 by means of bolts 6 and nuts 22. An armature 17 has a free enddisposed between the pole ends 2, 3 and 4, 5 and is secured proximateits other end to the frame 23 by means of posts 18 and 20 and lock nuts19 and 21.

An adjusting screw 16 is screw-threaded through the frame 23 and acts asa tensioning member upon the armature 17 at a point intermediate theposts 18 and 20 and is adapted to effect a degree of adjustability ofthe armature.

A pair of snugs 8 and 9 are attached, respectively, to the faces 2 and4- of the pole pieces in any suitable manner and are engaged by a conel0, adjustment of which will move the snugs 8 and 9, and their polepieces, in a manner to. be described in detail later. 1 j I The faces ofthe snugs engaged by the cone 10 are shaped to conform to the curvatureof the cone, and this cone is screw-threadedly mounted by means of ascrew. 11 in a bearing 12. The

bearing 12, in which the screw 11 is mounted, is itself slidably mountedin a portion 15 of the frame 23. The threaded portion of an adjustingscrew 13 engages a threaded portion in the bearing 12 and a collar orring 51 is rigidly attached to the screw 13 and is housed by a cap 50,which is in turn attached to the frame 23 by means of screws 52.

In the operation of the pole adjustment mechanism shown in Figs. 1 and2, it is assumed, for purposes of illustration, that the pole points 2and 3 are too close to the armature, during its maximum points of normalvibration, and the' pole points 4 and 5 are too far away. By turning thescrew 13 so that it moves the cone carrying member 12 upwards, the snug8 will move the pole points 2 and 3 away from the armature and the snug9, under the influence of some than the points 3 and 5. This differencein extent of movement of the pole points should approximate thedifference iii-extent of movement of the armature at those points. I

By adjusting the cone 10 either to the right or left the pole points 2,.4 and 3, 5 maybe made to simultaneously approach or recede from eachother; and by raising or lowering the cone 10 the pole points 2, 4 and3, 5 may be made to simultaneouslyapproachor recede from the armaturewhile remaining at the same distance from each other.] Byvirtue of thesetwo adjustments it is apparent that by adjusting the cone eithervertically or horizontally or .both, any desired spacing of the polepointswith respect to each other and to the armature may be effected. 1

The embodiment of the invention illustrated in'Fig. 3 is especiallyadapted to be used when,

'due to the type of polarization of the armature the point of maximumthrow of the armature 1'7 is upwards, and the device was originallyproperly centered for vibrations of equal directional amplitude, itbecomes necessary to move the pole ends 2 and 5 upwards or away from thearmature and the pole pieces 3 and i upwards or towards the armature.This adjustment may be-effected merely by moving the cone 10 upwardsfrom its old axial position AA to its new axial position B-B. By moving.cone. 10 to the right separation of the snugs 3 and 9 is effected andwill cause the pole points 2 and .4: to move away from the armature andpoints 3 and 5 to approach it. The form of adjustment just described isrendered effective by locating pivotal point 6 at the center about whichthe armature 17 vibrates, so that the pole pieces 3 and 5 will move onan are having radius r and-the pole pieces 2 and a will move about anare having radius R, which radii are the radii of the portions of thearmature proximate these pole pieces. It is apparent that the structureshown in this modification of the invention is especially effective whenan armature vibrates to afgreater amplitude in one direction than inanother.

, The application of the adjustments for a ringing system with anarmature movable around a rotating axis is shown in Figse and 5. In thiscase there are rotatably located on a permanent magnet]. both pairs ofpole pieces 2 and 3, and '4 and 5 on' bearing 6. The signal alternatingcurrents pass through coils 7. .On armature 17 is provided a hammer 25.Adjustment of .the pole pieces is effected by cone 10 which is shiftedagainst the oblique surfaces of the snugs 8 and 9 fixed to the polepieces when screwli is turned. If the cone 10 is turned to the right, itmoves the surfaces of snugs 9 and 8 apart and, consequently,.rernovesthe pole pieces 2, 3 and i, 5 from the armature 1'7. When the cone isturned to. the left-the pole pieces are moved toward the armature underthe tension of spring 30.

Referring to Figs. 6 and 7, the pole pieces are .provided with bearings6 attached to the poles of the magnet 1. The armature end 17 passesbetween the pole pieces and the body portion is supported by nutsandbolts at 33, 34 and 35. The screw 16 serves to adjust the position ofthe armature in relation tothe pole pieces.

The two yokes or extensions 31. and 32 are A screw 37 engages anextension 41 of the block 36 and serves to tilt it when turned in eitherdirection. The tilting of the block moves the opposite direction aboutthe bearings 6, so the,

distance between pole pieces and armature may be varied as This movementis produced due to the fact that the block 36 as fastened to the polepieces pivoted at 6. It

naturally follows that when the block 36 is tilted, one yoke end will beforced upward and the other forced downward causing their respectivepole pieces to rotate in opposite directions. 1

Referring to Fig. 8, the armature i? is shifted in position between thepole pieces by the screw i6. Only two similar pole pieces 2 and 3 areshown, for simplicity, but on the other side of the armature there wouldbe two opposite pole pieces.

When the armature 3.? is vibrating, its end opposite the pole piece 2describes a larger path or arc than that opposite the pole piece 3. Foradjustment, the pole pieces 2 and 3 are moved about the bearing 6. Thepole piece 2 with the radius (R) describes a large are about the bearing6, while the. pole piece 3 describes a smaller 1 From theforegoingdescription. it will be noted that provision is made foraccurate adjustment of the pole pieces in relation to the armature of anelectro-"magnetic device as applied to loud speakers, telephone ringersorsimilar systems. It will be readily apparent that variousmodifications may .be made to the structural arrangements withoutdeparting from the spirit of my invention.

What is claimed is:

1. A device comprising an armature and pole pieces, meansfor adjustingthe zero position of the armature between said pole pieces, and a singleadjusting means for moving the pole pieces toward or awayfrom saidarmature.

*2. A device comprising an armature and pole pieces, means for adjustingthe position of the armature between saidpole pieces, and, a singleadjusting means for moving the pole pieces toward or away from saidarmature, the movement of said pole pieces in either direction being inare paths.

3. A device comprising an armature and two similar pole pieces pivotedaround a common axis, means for adjusting the position of the armaturebetween said pole pieces, and means for mov-' ing saidpole pieces aroundsaid axis to move toward or away from said armature.

4. A device comprising an armature and two similar pole pieces rotatableabout a common axis and having their surfaces facing the armature lyingin different planes.

5. A device comprising an armature and a plurality of pole pieces,wherein the similar pole pieces facing the armature lie in differentplanes, a single adjusting means for simultaneously moving said polepieces in relation to said armature.

6. A devicecomprising an armature and pole pieces, means. for causingsaid pole pieces to jointly. approach or move away from said armature,and means for moving said pole pieces to individually approach or moveaway from said armature.

' 7. A device comprising an armature and pole pieces, means for causingsaid pole pieces to jointly approach or move away from said armature,and means for moving said pole pieces to individually approach or moveaway from said armature, the movement of said pole pieces in eitherdirection being in circular paths.

8. A device comprising an armature and pole pieces, means for causingsaid pole pieces to jointly approach or move away from said armature.and means for moving said pole pieces to individually approach or moveaway from said armature, the joint and individual moving meanscomprising an adjusting member whose moving axis is adapted to beshifted against the symmetrical axis of the pole pieces.

9. A device comprising an armature and two movable pairs of polepiecesya single adjusting means for moving said pairs of pole piecestoward or away from said armature.

10. A device comprising an armature and two movable pairs of polepieces, means for moving said pole pieces in arc paths toward or awayfrom said armature.

11. A device comprising an armature and. two movable pairs of polepieces, means for moving the similar pole pieces on circular pathshaving different radii, toward or awayfrom said armature.

12. A device comprising an armature and two movable pole pieces, meanscomprising a cone shaped member for causing the movement of said polepieces toward or away from said armature.

13. A device comprising an armature and two movable pole pieces, a coneshaped adjusting member movable in one plane to adjust the position ofsaid pole pieces in relation to said armature, and means for moving saidcone shaped member in a different plane to provide a differentadjustment for said pole pieces.

I 14. A device comprising an armature and tw movable pole pieces, a coneshaped adjusting said arma-

